987 boxster 2.7 fan noise

[craigdonnelly]

hello, I bought my Boxster 987 2.7 on Tuesday night. I have noticed that the fan comes on more than I would expect. For example tonight I drove about half an hour to football. Played football for an hour and returned to the car to go home. I turned the key so that the electrics were on but the engine was not. Straight away I heard the fan come on and looked at the temprature gauge and it was at half way or 80/90 degrees position. I thought that can't be right because the car was stationary for about 60-90 minutes and should have cooled. Any ideas???

Also as a new owner is there anything I should look out for or be aware of? cheers

[khushy]

I recently had a fan-on problem with my car - control unit at fault and fixed under warranty.

Khushy

[Pope]

Which fan?

Front fans (2 of, 1 under each headlamp) are infinitely variable (can run at any speed from just turning to flat out depending on cooling requirement) and will also run whenever the AC is on.

Engine bay fan (behind OSR air vent) runs whenever the engine bay temp is above a specified threshold. The engine bay is fairly well sealed so retains heat, therefore the fan runs quite a lot.

A front fan can be blocked by debris (stones and such) at which point the remaining fan will be activated to compensate (usually flat out) start the car and have a walk round it, if one fan is running and one isn't, turn the engine/ignition off and try to free the stuck fan - you can access the fan through the arch vent in front of each front wheel with a long screwdriver, turn the fan back and forth to dislodge any debris until it turns freely then retry the fan - 99% of the time this is successful.

In answer to your 'what to look out for' the 987 is a great car; very well built and reliable. Look for even tyre wear - the geometry is fully adjustable so can move out of spec. Any strange noises should be checked out - suspension especially - as they are generally quiet cars and wear manifests itself initially as noise rather than a deterioration in handling. With Autumn coming up, make sure any drains and vents are kept clear of leaves and other crud - especially battery area (under front lid trims) and under the hood (put the roof half way back and check the area under the raised 'tin lid') leaves can block the drains leading to issues when water collects.

HTH

[Billwood42]

Hi, So, the fans come on when the air con is used. Do they come on full, or just a little, as required? My fans come on full, and are very noisy, and I don't think this is right. Bill

[craigdonnelly]

Thank you for your reply. The fan noise is coming from the rear behind the drivers seat but...

I checked the water and oil levels and the water levels are fine but found "gunk" under the oil filler cap. Also when I opened the "boot" there was condensation above the water/oil cap area. The car is under warranty. Any ideas???

(I took pictures but can't upload for some reason)

[ChipsAndCheese]

Pope said:

Engine bay fan (behind OSR air vent) runs whenever the engine bay temp is above a specified threshold. The engine bay is fairly well sealed so retains heat, therefore the fan runs quite a lot.

If I have done a fairly long run then parked up for a while, when I return and fire up the engine this fan does kick in straight away. I have found that if you get going again and get a bit of air in the vent it shuts off again shortly after.

craigdonnelly said:

I checked the water and oil levels and the water levels are fine but found "gunk" under the oil filler cap.

Apparently gunk can form under the oil cap if you do lots of very short journeys. I think the usual advice is to clean it off, take the car for some decent length runs and just keep an eye on it.

[khushy]

oil filler gunk = NORMAL!

[craigdonnelly]

SO is the oil filler "silver/grey gunk" normal?

Chipsandcheese that is exactly what my car is doing.

[Pope]

Yes, normal - the oil filler is a remote type - a fair distance from the engine and made from highly insulated plastic, the filler never gets hot enough to evaporate off any condensation / vapour created during normal engine use, the result is a collection of oil vapour, moisture and other combustion
by-products condensing at the furthest / coolest point.

Clear it out periodically if it bothers you but it generally can be reduced if the motor is given a thorough drive (do you need any other excuse really? )

[cslwannabe]

Pope do you mean the fan can be accessed via the slats without even removing the front wheel?

[Rockster]

craigdonnelly said:

Thank you for your reply. The fan noise is coming from the rear behind the drivers seat but...

I checked the water and oil levels and the water levels are fine but found "gunk" under the oil filler cap. Also when I opened the "boot" there was condensation above the water/oil cap area. The car is under warranty. Any ideas???

(I took pictures but can't upload for some reason)

As others have covered the fan coming on is the engine compartment fan and it can come on even after the engine has been off a while. My 02 Boxster's engine compartment fan doesn't run when the car is locked but occasionally on a hot day I'll go back to the car after nearly an hour away and when I unlocks the car the engine compartment fan comes on.

(My Turbo's engine compartment fan can come on even when the car is locked and on a real hot day the fan can cycle on and off several times over the span of a half an hour or so.)

The gunk under the cap is just some water vapor combing with oil vapor. That area of the engine's internal space is the coolest so water vapor will condense there. You probably need to take the car out on a nice long drive once in awhile to get the oil hot enough long enough to boil out the water vapor. Also, you need to consider more frequent oil/filter services.

The condensation above water/oil cap area is probably from a leaking coolant tank cap. This can allow vapor to escape after the hot engine is shut off and the heat load of the engine raises coolant temperature and pressure. A surprising amount of water can leave the system this way. With my Boxster the low coolant light came on. I topped up the tank with nearly a gallon of distilled water. Using the car almost every day about a month later the light came on again. Down almost a gallon again.

Replace the cap. It doesn't cost much. Keep an eye out for any condensation though. It could be coming from a crack in the coolant tank.

The tank can open up as I covered above after the hot engine is shut off and heat causes the coolant to get hotter and increase its pressure. A bit of coolant seeps out and the water vapor is what you see. The system cools down and the crack closes and remains closed until the next time you shut of the hot engine.

Given the gunk under the oil filler tube cap you probably don't get the engine that hot that often though.

You can run a pressure test on the car's cooling system by making sure the coolant level is ok, not low but not too high either, then driving the car around until the engine is nice and hot. Leave the AC off. Drive around until you hear/feel the radiator fans come on. Back home in the driveway raise RPMs to 1500 and hold until the fans come on. Then shut off the engine. The heat load will raise the coolant temperature and pressure and if the tank has a split it will probably gush hot coolant from the pressure increase.

[Pope]

cslwannabe said:

Pope do you mean the fan can be accessed via the slats without even removing the front wheel?

Yes; to a fashion. Put the steering on full lock, illuminate the area in the arch with a torch and you'll see the fan turn the fan with a long thin screwdriver

Any faults in the fan will require more disassembly though

[cslwannabe]

Thanks pope - I still found it tricky to see although counter intuitively it was better with the wheels turned outwards rather than inwards. I did find I could reach the fans from underneath the front bumper however and turn them by hand.